refactor: remove frontend, move JSONs to json/ top-level

- Archive frontend to community-scripts/ProxmoxVE-Frontend-Archive
- Move frontend/public/json/ -> json/
- Update workflow paths in 5 actions:
  - update-versions-github.yml
  - update-json-date.yml
  - push-json-to-pocketbase.yml
  - delete-pocketbase-entry-on-removal.yml
  - autolabeler.yml
- Remove frontend-cicd.yml (no longer needed)
- Clean up .gitignore (remove frontend-specific entries)

json/privatebin.json

@@ -0,0 +1,35 @@
+{
+    "name": "PrivateBin",
+    "slug": "privatebin",
+    "categories": [
+        12
+    ],
+    "date_created": "2025-01-29",
+    "type": "ct",
+    "updateable": true,
+    "privileged": false,
+    "interface_port": 80,
+    "documentation": "https://github.com/PrivateBin/PrivateBin/wiki",
+    "website": "https://github.com/PrivateBin/PrivateBin",
+    "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/privatebin.webp",
+    "config_path": "/opt/privatebin/cfg/conf.php",
+    "description": "PrivateBin is a minimalist, open-source pastebin where the server has zero knowledge of pasted data. Data is encrypted/decrypted in the browser using 256-bit AES.",
+    "install_methods": [
+        {
+            "type": "default",
+            "script": "ct/privatebin.sh",
+            "resources": {
+                "cpu": 1,
+                "ram": 1024,
+                "hdd": 4,
+                "os": "debian",
+                "version": "13"
+            }
+        }
+    ],
+    "default_credentials": {
+        "username": null,
+        "password": null
+    },
+    "notes": []
+}